MOSFET-Switch-Based Transformerless Single-Phase Grid-Tied Inverter for PV Systems

Nonisolated photovoltaic (PV) inverters based on a single high-frequency MOSFET power switch have become more and more popular recently. Among these topologies, the conventional buck–boost inverter is fairly achievable but has low efficiency, whereas the buck with boost inverter has the main drawback that its circuit includes too many devices. In order to outperform these topologies, a new MOSFET-switch-based transformerless inverter topology sharing one common ground between the PV source and the grid is presented in this article. The inverter experiences zero leakage current and only one energy-regulating inductor is equipped. The basic principle of operation is studied based on an equivalent circuit analysis. Moreover, the control strategy adopting dead-beat controller for the proposed inverter is designed and introduced in detail. Finally, a 110-V/50-Hz/500-W prototype is built up to test the correctness of the theoretical analysis. According to the measurement results, the efficiency of the prototype is 98.81% and 95.89% in light- and full-load situations, respectively. According to the experimental results, it can be verified that the proposed dc/ac inverter exhibits satisfactory steady-state and transient performance.